The Raman Spectra of Polybutadiene Rubbers

1970 ◽  
Vol 43 (2) ◽  
pp. 322-332 ◽  
Author(s):  
S. W. Cornell ◽  
J. L. Koenig

Abstract The Raman spectra of cis-1,4-, trans-1,4-, and 1,2-polybutadiene are presented. Analysis of the spectra of these model compounds, and the normal coordinate results, enable the Raman frequencies to be classified by configurational structure type. The Raman carbon—carbon double bond stretching vibrations can be used to describe uniquely the structure content in polybutadienes.

1970 ◽  
Vol 43 (2) ◽  
pp. 313-321 ◽  
Author(s):  
S. W. Cornell ◽  
J. L. Koenig

Abstract The Raman spectra of cis-1,4-, trans-1,4-, and 3,4-polyisoprene are presented, and the frequencies are classified by configurational structure type. The stretching frequency of the carbon-carbon double bond vibrations are used to describe structure content. Only Raman bands characteristic of total 1,4 content and total vinyl content can be observed. Tentative values of structure content determined by both peak height and peak area are presented for two mixed structure rubbers.


1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.


1974 ◽  
Vol 29 (9-10) ◽  
pp. 647-653 ◽  
Author(s):  
Hans Bürger ◽  
Reint Eujen

The IR and Raman spectra of SiH3⊖, SiH3SiH2⊖, (SiH3)2SiH⊖, (SiH3)3Si⊖ and their deuterated derivatives have been recorded in HMPT and HMPT-d18 solutions. Most normal vibrations have been identified. The SiH and SiSi stretching vibrations are considerably lower than for analogous silanes and silylphosphines, ∼ 2050 and 1850-1900 cm-1 being characteristic for SiH3 and SiH⊖n groups respectively. The assignments are proved by a normal coordinate analysis, and force constants have been calculated. The negative charge is mainly localized on the trivalent Si atom and the lone pair acts repulsively rather than strengthening the SiSi bond through (p→d)π effects.


1971 ◽  
Vol 25 (3) ◽  
pp. 352-355 ◽  
Author(s):  
Kazuo Nakamoto ◽  
James Takemoto ◽  
T. L. Chow

The Raman spectra of [64Zn(NH3)4]I2 and its 68Zn analog have been measured in the crystalline state. The Zn–N stretching vibrations have been assigned based on the observed metal isotope shifts. These shifts have been compared with theoretical values obtained from a complete normal coordinate analysis on the [Zn(NH3)4]2+ ion.


1955 ◽  
Vol 33 (12) ◽  
pp. 811-818 ◽  
Author(s):  
B. P. Stoicheff

The pure rotational Raman spectra of allene, allene-d4 and allene-1,1-d2 were photographed in the second order of a 21 ft. grating. Two plates of each spectrum were analyzed yielding the following values for the rotational constants:[Formula: see text]These constants lead to the value r0(C=C) = 1.3088 ± 0.001 Å. Also if a value of r0(C—H) = 1.07 ± 0.01 Å is assumed, then [Formula: see text]. It is noted that the length of the carbon–carbon double bond in allene is significantly shorter than that in ethylene.


1981 ◽  
Vol 46 (11) ◽  
pp. 2613-2619 ◽  
Author(s):  
Jiří Toužín

Available data on infrared and Raman spectra of S4N4 in solid state and solutions have been verified and completed. On the basis of normal coordinate analysis an attempt has been made to define with more precision the interpretation of vibration spectra of this compound given in earlier reports.


1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).


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